The Ukrainian military says four of its soldiers have been killed in clashes with Russian-backed separatists in eastern Ukraine in the past day.

Military spokesman Andriy Lysenko said on August 3 that 15 other soldiers had been wounded in the past 24 hours in fighting along the front line in parts of the Luhansk and Donetsk regions.

The casualties come as Ukrainian officials and rebel representatives began fresh talks in Minsk along with negotiators from Russia and the Organization for Security and Cooperation in Europe (OSCE) aimed at improving the conditions of a fragile cease-fire signed in February.

More than 6,500 people have been killed in eastern Ukraine since fighting began there in April 2014.